Hair cutting appliances, particularly electric hair cutting appliances, are generally known and may include trimmers, clippers and shavers. Electric hair cutting appliances may also be referred to as electrically powered hair cutting appliances. Electric hair cutting appliances may be powered by electric supply mains and/or by energy storages, such as batteries, for instance. Electric hair cutting appliances are generally used to trim or remove (human) body hair, in particular facial hair and head hair to allow a person to have a well-groomed appearance. Frequently, electric hair cutting appliances are used for cutting animal hair.
U.S. Pat. No. 6,968,623 B2 discloses a hair trimmer comprising a body, a cutting head including a blade set, an adjustable comb, wherein the comb is movable with respect to the blade set, an electric motor for driving the blade set to effect a cutting action, and an actuator assembly that is capable of moving the comb with respect to the blade set between a fully retracted position and a fully extended position, the actuator assembly comprising a comb carriage, a comb button connected to the comb carriage, wherein the comb button is actuatable to adjust the position of the comb relative to the blade set, and a lock button movable with respect to the comb button, wherein the lock button selectively prevents and permits movement of the comb button relative to the body. Consequently, manual adjustment of the length of the comb is enabled.
A comb for a hair cutting appliance, particularly a spacing comb, generally may be arranged as an attachable comb or an integrally formed comb. A spacing comb generally spaces a blade set of the hair cutting appliance away from the skin when the appliance is moved in a moving direction with respect to the skin during operation. Consequently, the spacing comb may enable to process/cut hair to a desired length, i.e. to a desired length of remaining hair at the skin.
Conventional hair cutting appliances may be fitted with a set of attachment combs, each of which associated with a distinct hair length. Consequently, a user of the appliance basically needs to replace an attachment comb by another one to alter the hair cutting length. Furthermore, manually adjustable comb attachments are known, as disclosed in U.S. Pat. No. 6,968,623 B2. Furthermore, also powered adjustment combs have been presented in recent years, as for instance disclosed in EP 2 500 153 A2. Typically, powered adjustment combs comprise a movable comb portion that is movable with respect to a blade set of the hair cutting appliance, wherein the movable comb portion is coupled to an actuator, particularly to an electromotor and/or an electric powertrain.
Length adjustment mechanisms of a conventional mechanical kind typically transfer or convert a manual operating movement applied by the user into a resulting adjustment movement. It has been observed that, for small length values, a rather fine-graduated length adjustment is desired. By contrast, for rather large hair length values, a coarse-graduated length setting is desirable. Hence, conventional length adjustment mechanisms typically represent a tradeoff between a capability of fine adjustment and a quick user-friendly adjustment setting.
There is thus room for improvement in length adjustment mechanisms.